CODEWITHSUNDEEP
c
coderGtm
coderGtm

Reputation: 121

How to get string as return value from function in C?

I am a newbie in C and am trying to make a hangman game where a player will have to guess a random word selected by the program. But I am stuck in getting the word. I tried a lot and found some answers on SO but could not relate it to my case.

Here's the code:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

char dictionary[3][15] = {"food","cat","coder"};
//15 is max length of each word

char getWord() {
    srand(time(0));
    char *random_elem = dictionary[rand()%3];
    printf(random_elem);
    return random_elem;
}


void gamePlay() {
    *word = getWord();
    printf(*word);
    return;
}

int main() {

    printf("Welcome to Hangman\n");
    printf("------------------------------------\n\n");

    gamePlay();
}

The printf in the getWord() works but not in gamePlay()

The following error is generated:

<stdin>:11:12: warning: format string is not a string literal (potentially insecure) [-Wformat-security]
    printf(random_elem);
           ^~~~~~~~~~~
<stdin>:11:12: note: treat the string as an argument to avoid this
    printf(random_elem);
           ^
           "%s", 
<stdin>:12:12: error: cannot initialize return object of type 'char' with an lvalue of type 'char *'
    return random_elem;
           ^~~~~~~~~~~
<stdin>:17:6: error: use of undeclared identifier 'word'; did you mean 'for'?
    *word = getWord();
     ^~~~
     for
<stdin>:17:6: error: expected expression
<stdin>:18:13: error: use of undeclared identifier 'word'
    printf(*word);
            ^
1 warning and 4 errors generated.

OS: Android 11 App: Cxxdroid

If that might help

Upvotes: 0

Views: 315

Answers (2)

Lundin
Lundin

Reputation: 213842

In this case you can return a pointer, since the actual strings are declared with static storage duration (if they are local variables, you can't do that). You should however const-qualify the pointer since string literals are read-only. Fixed code:

const char* getWord() {
    static const char dictionary[3][15] = {"food","cat","coder"};
 
    srand(time(0));
    const char *random_elem = dictionary[rand()%3];
    puts(random_elem);
    return random_elem;
}

I moved the variable declarations inside the function since global variables should be avoided. static ensures that they still have static storage duration so you can return a pointer to them.

The warnings about "format string is not a string literal" is nothing to be concerned with in this case. If you replace printf with puts they should go away.

Upvotes: 1

Kerasiotis Ioannis
Kerasiotis Ioannis

Reputation: 51

The right code is the above.

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

char dictionary[3][15] = {"food","cat","coder"};
//15 is max length of each word

char* getWord() {
    srand(time(0));
    char *random_elem = dictionary[rand()%3];
    printf("%s\n",random_elem);
    return random_elem;
}


void gamePlay() {
    char *word = getWord();
    printf("%s\n",word);
    return;
}

int main() {

    printf("Welcome to Hangman\n");
    printf("------------------------------------\n\n");

    gamePlay();
}

Upvotes: 2

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